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10/20/2017 1:01:18 AM
9/22/2017 12:11:25 AM
Posted: 8/8/2005 3:56:19 AM EDT
Well, we've finally gotten to the point at the new house where I need some help. I'll give some details first.

The new house is built on a slab. Sometime after the original owners constructed the house, they must have realized that we are, after all, on the fringes of Tornado Alley and that the house, being built on a slab, didn't have a basement. They subsequently built a detached garage a short distance from the house that has a storm shelter under it.

The storm shelter is a room approximately 10x12, built of cement block with poured (and, I assume, reinforced) concrete floor and roof slabs. The floor has a built-in sump pump basin, which ties into my problem. The walls and floor of the shelter have been painted with a white, thick, presumably waterproofing paint that is chalking and scaling very badly.

Now, the problem is that the shelter has about 2' of water in it at all times. It appears that, sometime after construction of the shelter, the water table must have risen to it's present level, about 2' into the shelter. I pumped the shelter out soon after buying the house but, since water kept leaking in, I unpluged the sump pump to see how far it would rise. When I initially pumped it out, it had about 3' of water in it, which is now down to the above mentioned 2', presumably because of the very dry summer so far.

Now, for the big question. Since the house doesn't have a basement and we do live in a tornado-prone area, the wife is after me to get the shelter into useable condition. If I can get the shelter pumped out and find out exactly where the water is coming in and patch any cracks, then I just have to deal with the water seeping through the block and floor. Provided I can get most of the existing paint off the block, do you think something like UGL's Drylox would suffice for waterproofing the shelter? Given that there only appears to be about 2' of water, the pressure from the ground water shouldn't be too bad but, since it is groundwater, it will be constant and steady. I know Drylox works well for seepage but how about the steady, constant pressure from the groundwater?

Another question is, since the shelter does have a sump basin, would I be better off drilling a few holes in the walls/bottom of the basin to give the groundwater a safe place to go? My problem with this is that if something happens to the sump pump or we lose power, the shelter would then fill up very quickly since the water now has an unobstructed flow into the shelter. I plan on a battery back-up for the pump but, as we all know, Murphy strikes at the worst times and, with my luck, we'll be in the shelter, the power will go off and the battery backup will decide to crap out.

Digging the sides of the shelter out to fill with gravel for drainage, which I don't know if it was done or not when constructed, is out. This is because, after initial construction, the garage was added onto on one side and the back, with the additions concrete-slabbed and sticking out over the side and back of the shelter. Because of this, excavation would be extensive and expensive, requiring considerable manpower and bracing of the slabs. Most of our savings went into downpayments and improvements and is practically non-existant at this time.

So, what say you ARFCOM? Am I out of luck with this or does someone have any bright ideas? I'd really like to get this shelter useable since, with the concrete roof being well tied down and about 1.5' thick, we should be able to withstand storms that would devastate everything around us. If it's not going to work, however, I'm not wasting much time on it. As always, thanks for looking and for any and all assistance.

Bub
Link Posted: 8/8/2005 4:10:09 AM EDT
2' = 2 feet of water? Or do you mean 2" = 2 inches of water?
Link Posted: 8/8/2005 4:19:35 AM EDT
Sealing the inside of the walls will not be a good long term solution. The water has to have somewhere to go before it gets to the shelter. If you can get it sealed on the outside and allow the water to drain away from the structure via gravity drainage, it should be fine. Any other efforts will be stopgap in nature and will not work in the long run.

If the excavation is un doable, you might be able to build a "false floor" in the shelter, and use the area under the floor as a large bilge from which you operate your pumps. The humidity in the shelter will always be 100% if you do this, and metal and wood items will deteriorate quickly.
Link Posted: 8/8/2005 4:24:11 AM EDT
Try submitting your question to:

bryon@buildersacademy.com

HH
Link Posted: 8/8/2005 4:33:02 AM EDT
[Last Edit: 8/8/2005 4:34:50 AM EDT by jchewie]
Do you have any idea if the shelter has or had foundation drains? Installing a drainpipe all the way around the structure at the footing level, tieing that drain into the sump pump, and backfilling with small gravel is the only way to cure this.

Edit -- unless you can do as the poster above suggested and route the drain to an area down hill from the shelter.

Link Posted: 8/8/2005 4:36:27 AM EDT
Well, first the bad news: You are fresh out of luck.

Now, the good news: I just saved alot of money by switching to GEICO.

PS- Short of a big plastic bowl to crawl in, you are never going to keep water out of that space.
Link Posted: 8/8/2005 4:50:17 AM EDT
If the water table is that close to the surface, that would be the reason the house is on a slab. [/obvious off]

You'll never be able to keep water out of that shelter in that case. Call a well drilling contractor to confirm the location of the water table.
Link Posted: 8/8/2005 5:09:40 AM EDT

Originally Posted By Wobblin-Goblin:
Well, first the bad news: You are fresh out of luck.

Now, the good news: I just saved alot of money by switching to GEICO.

PS- Short of a big plastic bowl to crawl in, you are never going to keep water out of that space.

+1 Get some big sheets of glass and line the inside of the shelter with it and silicone the edges. That might work to keep water out. Like a reverse fish tank. But in reality I think you and the wife are screwed. maybe build a new one on higher ground or dozer up some higher ground. Shit pour a 12 slab and build 4 walls with 8" block double thick filled with mortar. get some steel to build a re-inforced ceiling roof system with concrete
Link Posted: 8/8/2005 5:20:36 AM EDT
[Last Edit: 8/8/2005 5:21:03 AM EDT by Admiral_Crunch]
I think the above-ground tornado-proof bunker approach is going to be your best bet. And if you wanted to, you could always build up a hill around it (minus an approach for the door). An earthen bank on all sides would deflect winds/debris over the structure, provide additional reinforcement, and make it look better than a giant concrete block in your backyard.

If it were me, I'd probably build it as a reinforced addition to your house and just put siding(or whatever) up over the concrete walls. Basically a saferoom addition. If it's strong enough, it'll survive a direct hit from a tornado that would flatten the rest of the house, and it doesn't have to be underground if you don't want it to be.

Of course, I'm no professional, so TIFWIW.
Link Posted: 8/8/2005 5:26:16 AM EDT

Originally Posted By AeroE:
If the water table is that close to the surface



I think that may be the first thing I wanted to prove/disprove.

I would check the water table in the area adjacent to the "room", and see where it is, to see the potential for this problem to be beat. If the table is higher than the rooms floor, I agree with Wobblin, you are fresh out of luck.

Link Posted: 8/8/2005 8:12:31 AM EDT
This is what I was thinking, too. I'm really not sure if this is the water table or not but, even if it wasn't, if it would be strictly a drainage problem, the water came in, it ought to go back out, right? It's not going back out unless I pump it out.

I've asked the neighbors about basement problems with water. Even the closest to us, whose house is a good 5-6' down the hill from us, has no problems aside from some seepage during rainstorms. Kinda indicates the water table should be lower than our shelter.

And, yes. I meant 2 FEET of water in the shelter. Judging by the gunk on the walls, it's been as high as 4 FEET but is normally at 2-2.5 feet.

Guess I try to verify how high the water table is where the shelter is, then. Even if the water table is lower than the shelter, the water is coming from somewhere, hell, there might be a spring under it for all the water that's there!

I'd really like to try and get it as dry as possible. Hell, if I can, there's room there for some supplies so a bad storm would be bearable instead of miserable in a small, bare concrete room.

As for foundation drains, your guess is as good as mine. When I saw that there was a sump basin, I thought that maybe there were and they were running into the sump basin but there are absolutely no openings in the sump basin at all, it's all concrete.

Thanks for the help, guys. I thought I might be screwed but thought that maybe, just maybe, there was a miracle product out there that would dry up the water and prevent more from coming in till Doomsday. A fantasy, I know, but I was hoping. Thanks again.

Bub
Link Posted: 8/8/2005 8:34:26 AM EDT
If the neighbors house is 5-6' below your home then it is DEFINITLY a drainage problem. The room needs excavited, drain pipe and gravel installed, and new walk ways installed. While it is open and exposed I would seal the outside and add some insulation while I was there.
Link Posted: 8/8/2005 8:36:31 AM EDT
[Last Edit: 8/8/2005 8:37:23 AM EDT by Cyclic]
Doh, double tap.
Link Posted: 8/8/2005 8:56:06 AM EDT
Until you figure out where the water is coming from and *if* it can be stopped, then you are pretty much screwed. Also, even if you were to make the shelter completely waterproof so that absolutely no water was coming in from the outside, you may still yet have problems until you handle the source. With that much water the shelter can "float" if it were totally waterproof. It very well would at least crack the floor of the garage and/or lift a bit. I have seen this with empty septic tanks and a high water table.

Find the source of the water and if it can be drained elsewhere.
Link Posted: 8/8/2005 8:57:30 AM EDT
Ummm, this is a NEW structure? Have you gone back to the contractor who dug/ built this thing to let them know of the problem? You may have some legal recourse. Two FEET of water is alot to have mysteriously appear. hen I agree w/ all the others- unless you correct the drainage problem you will always have water inside. No pump and fresh paint will be able to compete w/ constant ground moisture/rain invasion. Another place w/ lots of competent builders would be finehomebuilding.com. They have a chat area as well w/ many knowledgeable folks willing to help. Good luck!
Link Posted: 8/8/2005 10:31:52 AM EDT
You are out of luck, unless you totally excavate the garage, expose the footing, apply a waterproofing system to the footing and foundation walls, and then hope for the best. Hydraulic pressure may still force water up through the slab if there are cracks in the floor.

Link Posted: 8/8/2005 10:46:17 AM EDT

Originally Posted By bub75:
This is what I was thinking, too. I'm really not sure if this is the water table or not but, even if it wasn't, if it would be strictly a drainage problem, the water came in, it ought to go back out, right? It's not going back out unless I pump it out.


Bub


I don't get this. If it IS the water table, the reason it's coming in is because the natural level of the water is above the floor of the basement.

If this is indeed the case, then it's NEVER going to drain on its own, it's found its level.

How long has the pump run?

What I mean is, if you run it for, say, a week, then shut it off during a dry spell, does it still fill up?
Link Posted: 8/8/2005 6:56:21 PM EDT
This is FAR from new construction. The shelter is, I'm betting, 40+ years old. I'm also betting that whoever put it in is LONG dead!

I can run the pump for an hour or so (1/2HP submersible sump pump- this thing moves so much water I could start a wave pool!) and get the water level down into the sump basin. If I leave the pump off for a day or two, it's filled back up again. I haven't tried this for a few weeks since there are lots of other things to do. We were having some rain then, maybe it will make a difference now. I'm going to try it again on Wednesday, my next day off. If it holds true to form and fills back up in a day or two, I'm betting it's a high water table and we're screwed.

I already know I'm going to have to redirect the downspouts, they run down the side of the garage and have just an elbow on the end to shoot the water out. The trouble is, it only shoots out 6-8" then hits the ground. I'm thinking that, if I trench some 4" PVC and run the water a good 8-10' away from the garage, it'll help out some. The land gently slopes way from the garage so other runoff shouldn't be too big of a concern.

Digging out around the garage is, most likely, out. As I posted above, the garage has been added onto at some point in the past so that the additions, on concrete slabs themselves sticking out past the shelter's footprint, would have to be braced and shored to dig out under. I'm not good enough to do it myself and, right now, we can't afford to have it done. I don't know if gravel and drainage was done when it was originally built. The lady who lived here before us died 2-3 years ago and none of her family knows anything about the design/build details of the garage/shelter.

The shelter was like this when we bought the place. The trouble was, the entrance (which is in the garage) was boarded up and we weren't allowed to unboard it and look around because of the realtor being liable if we fell in or something. I thought it had water in it but, like I said, wasn't allowed to look. In the grand scheme of things, it wasn't (and, if you get right down to it, still really isn't) really important and, even with the problem, we got a KILLER deal on the house. The wife and I knew our closest neighbors before we even thought about buying this place and they have a basement. We've already been told that, if necessary, we can go there in the event of needing a shelter and, if they aren't home, we already have permission to break a window out of the back door to get in, if necessary. It's just that the shelter is already there. If I can figure this out, it would be nice to be able to use it.

Thanks for the help, all. Like I said, I was hoping that someone knew of a miracle solution that I didn't know about. It was a long shot but still worth asking.

Bub
Link Posted: 8/8/2005 7:03:34 PM EDT


Sounds like a job for TANNERITE!
Link Posted: 8/8/2005 8:23:07 PM EDT
Well, on the positive you've got yourself a great cistern.
Link Posted: 8/8/2005 8:37:29 PM EDT
Errr.....
Get a current survey of your land to find out where above sea level your house and out building is sitting.

Then get a well driller out there to drill a couple of holes to find out where the water table is.

Then find out if there IS a natural spring or underground river under your buildings.

Finally, find out if there is any type of a water main under your buildings and see if it is leaking.

I thought that sump pumps were hooked into a toilet level thingie and that when the water level got above a certain point the sump pump turned on automaticly.

If you were talking about a couple inches of water you could use DriCore:
www.dricore.com/en/eindex.htm
Link Posted: 8/9/2005 4:47:19 AM EDT
How close is the shelter to your septic tank and drain field?
Link Posted: 8/9/2005 4:52:48 AM EDT
tow wet feet in a hole with a cement roof is better than a tornado in your ass. is what i always say...
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